{"id":"UBUNTU-CVE-2018-10903","details":"A flaw was found in python-cryptography versions between \u003e=1.9.0 and \u003c2.3. The finalize_with_tag API did not enforce a minimum tag length. If a user did not validate the input length prior to passing it to finalize_with_tag an attacker could craft an invalid payload with a shortened tag (e.g. 1 byte) such that they would have a 1 in 256 chance of passing the MAC check. GCM tag forgeries can cause key leakage.","modified":"2026-01-30T00:45:52.252077Z","published":"2018-07-20T00:00:00Z","related":["USN-3720-1"],"upstream":["CVE-2018-10903"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2018-10903"},{"type":"ADVISORY","url":"https://ubuntu.com/security/notices/USN-3720-1"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2018-10903"}],"affected":[{"package":{"name":"python-cryptography","ecosystem":"Ubuntu:18.04:LTS","purl":"pkg:deb/ubuntu/python-cryptography@2.1.4-1ubuntu1.2?arch=source&distro=bionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.1.4-1ubuntu1.2"}]}],"versions":["1.9-1","2.1.3-3","2.1.4-1","2.1.4-1build1","2.1.4-1build2","2.1.4-1ubuntu1","2.1.4-1ubuntu1.1"],"ecosystem_specific":{"binaries":[{"binary_version":"2.1.4-1ubuntu1.2","binary_name":"python-cryptography"},{"binary_version":"2.1.4-1ubuntu1.2","binary_name":"python3-cryptography"}],"availability":"No subscription required"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2018/UBUNTU-CVE-2018-10903.json"}}],"schema_version":"1.7.3","severity":[{"type":"CVSS_V3","score":"CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N"},{"type":"CVSS_V3","score":"CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N"},{"type":"Ubuntu","score":"medium"}]}